Method of drawing glass.



PATENTED AUG.

4 SHEETS-SHEET 1.

INVENTOR 25.449, ML/MMM ...uuununumnnnu .H .....uwmmmuwnmu if l,

ULM.

J. H. LUBBERS.

METHOD 0F DRAWING GLASS.

APPLIUATION FILED szrfm. 1899.

No MODEL.

No. 766,274. PATBNTBD AUG. 2, 1904.

' J. H. LUBBERS. u

METHOD OF DRAWING GLASS.

APPLIMATION FILED s112135, 1899. .No MODEL. 4 SHEETS-SHEET 2,

WITNESSES INVENTOR y# zzn/w* w11 Maan/Mm,

may.

No. 766,274. PATENTED AUG. 2, 1904. J. H. LUBBERS.

METHOD OF DRAWING GLASS.

APPLICATION FILED SEP,T.5. 1899.

NO MODEL.

4 SHEETS-SHEET 3.

sums

*E fr? @2D witnesses mwen-ron a MJ.

PATENTBD AUG. 2, 1904.

J. H. LUBBERS.

METHOD OF DRAWING GLASS.

APYLIOATIOX FILED SEPT.5, 1399.

4` SHEETS-SHEET 4.

N0 MODEL.

INVENTOR y. um

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UNITED STATES Patented August 2, 1904.

JOHN H. LUBBERS, OF NElV KENSINGTON, PENNSYLVANIA.

METHoD'oF DRAWING GLASS.`

SPECIFICATION forming part of Letters Patent No. 766,274, dated August 2, 1904.

Application led September 5, 1899. Serial No. 729,435. (No model.)

To fall zl/'Lmn it may concern:

Be it known that l, JOHN H. LUBBERS, ot' New Kensington, in the county of lVestmoreland and State of Pennsylvania, have invented a new and useful Improvement in Methods of Drawing' Glass, ot' which the following' is a tull, clear, and exactdescription, reference being' had to the accompanying'drawings, forming' part ot' this specification, in which Figure l is a longitudinal section, partly broken away, showing' the drawing-chamber an'd leer ot' my improved apparatus. Fig'. 2 isa top plan view, partly broken away. Fig'.

3 is avertical cross-section through the leer, partly broken away t0 show the drawing'- frame in its chamber. Fig'. i is a cross-section ot' the drawing'-chamber, showing' the sheet after it has been severed. Fig'. 5 isa side elevation, partly broken away, showing' the receiving'-car at the end ot' the leer. Fig'. 6 is a longitudinal vertical section of the drawing-chamber, partly broken away and showing' my preferred construction ot' inutile-walls; and Fig'. 7 is a detail end view ot' the baitholder.

My invention relates to the making' of g'lass sheets, cylinders, or other articles by drawing' such articles from the molten bath by means ot a bait; and it is designed to provide a new and improved method ot' drawing' glass whereby commercial sheets or cylinders or other articles may be obtained.

To that end it consists of the following' items ot' invention: tirst, drawing' the article upwardly Yfrom the molten bath and retarding its cooling', so as to anneal it and prevent breakage; second, in shielding' the molten g'lass at the point at which the article is drawn 'from the surrounding' heat; third, in the drawing' ot' sheet-glass the gripping' ot' the edg'e portions ot' the sheet as it leaves the bath to prevent its narrowing; fourth, gripping' and stretching these edge portions of the sheet; tifth, in shielding' the glass at thelpoint ot' drawing' and artiticially cooling' the glass at this point, so that it may be drawn more rapidly; sixth, in retarding' the cooling' of the outer portions ot' a g'lass sheet more than the intermediate portion to prevent bending' or warping' of the sheet; seventh, in severing' the sheet or article at or near its lower end from the g'lass in the tank by a flame or otherwise, and, eig'hth, in annealing' the article after it has been drawn.

The invention further consists in the combination of steps, as hereinafter more fully described, and set t'orth in the claims.

ln the drawings, in which l show my invention arranged for drawing' glass sheets, 2

tory material, are secured to transverse bars 5, projecting' over the root', and they may be turned by levers 6, held in any adjusted posi- Y tion by pins T, placed in holes in inclined braces S. By this means the shields may be adjusted vertically to vary their distance above the glass-bath, and consequently the heat at the point of drawing' the sheet.

ln order to allow a more rapid drawing of the sheet than would otherwise be possible, l preferably provide cooling' devices, which in the form shown consist oit U-shaped watercooling' pipes 9, which rest upon the shields and swing' therewith, these watercooling' pipes being' provided with suitable inlets 10 and outlets ll, by which a continuous tlow ot' water may be maintained therethrough. These cooling' devices are not, however, nec* essary, though the drawing' must be done more slowly it' they are not used.

The glass-drawing operation is carried out between the shields by means of a bait 12, which may consist ot' a piece of sheet-glass, a metal strip. or a strip of clay or other refractory material, the glass sheet, it' such is used, being' clamped between the forked jaws 13 of the drawing-tool or bait-holder. These jaws are preferably provided with asbestos knots which contact with .the bait, the jaws being drawn together by suitable bolts 14. The vertical bars 15 of the drawing-tool are joined by a transverse bar18 and are provided with upper oppositely projecting hooks 16 and with lower oppositely-projecting lugs 17.

In the drawing operation the hooks 16 are engaged by the spring-jaws 19 ofthe drawing-frame 20, this frame having a guide 21 at one end engaging a vertical strip in the end of the chamber 23 and rollers 22 at the opposite end which contact with the walls, as shown in Fig. 3, thus keeping the frame in the proper position during lifting.

The drawing-frame is supported and moved vertically by chains or wire ropes 24, which may pass over suitable pulleys to a windingdrum actuated in any desired manner.

The drawing-chamber 23, into which the sheet rises as it is formed, is preferably made with hollow walls forming muflles, which are heated by suitable gas-burners 25, projecting into their lower portions, the flames and gases rising between spacing-bricks 26 and escaping through suitable outlet-ports 27 at the tops.

I have found in practice that where the horizontal zones of the drawing chamber are equally heated in a horizontal direction, as the edge portions of the glass will cool more rapidly than the intermediate portion, the sheet will be warped or curved, and to prevent this action I preferably form the drawing-chamber so that the sheet receives more heat in its outer portions than its intermediate portions, thus counteracting the quicker cooling of the outer portions and preventing warping or twisting of the sheet. Thus in Fig. 6 I show each hollow wall or muflle as provided with outwardly-inclined baiie plates or partitions 28. The burners 29 are located at the outer sides of these baffles, so that the rising heat-currents will heat the outer portions to a greater extent than the central or intermediate portions. This is an important feature of my invention, since if the heat is not applied more to the edge portions than to the intermediate part of the sheet the glass tends to warp, and I intend to cover the same, broadly, irrespective of the particular construction for obtaining this result.

The munie-chambers may, if desired, be open at their lower ends, so as to receive the heat from the furnace and the extension thereof, and in any form the heat of the walls is gradually decreased upwardly, so that the temperature of the sheet will be gradually re-` duced to prevent breakage during the setting or stiffening thereof.

The forehearth or extension 3 is preferably provided with end heating-burners 30 and a side burner 31, these being employed to keep the glass in the outer portion of the bath of the same consistency or temperature as that in the inner portion next to the main tank. The gases from these burners may be taken off through a downtake-flue 32.

In the opposite sides of the chamber 3 and between the shields are provided holes 33, through which tongs or grippers 34 may be inserted.v When the sheet is being drawn, the operators insert these tongs from time to time, as may be necessary, and seizing the edge portions of the glass draw or stretch it outwardly, so as to keep the sheet of about the same width and prevent its narrowing down. These portions of the sheet may be merely held against narrowing, if desired, though I prefer to positively pull or stretch the glass in a horizontal direction.

The upper 'end of the drawing-chamber is closed by hinged inwardly-projecting plates or dampers 35, which will swing upwardly to allow passage therethrough of the drawing tool and frame.

In carrying out the drawing operation the baitfholder is lowered until the bait enters the bath, and being heated thereby the glass will wardly from the bath and assume the form of` a sheet as it emerges, and this operation is continued until a sheet of the desired length has thus been drawn slowly upward. The thickness of the glass sheet so formed is easily changed by regulating the temperature of the molten glass and changing the position of the shields and the speed at which the bait is drawn upwardly. After the desired length of sheet has been obtained it may be severed from the glass in the bath by means of shears 36, supported from a suitable hanger 37, moving on track 38, as shown in Fig. 1, the shears being inserted through one of the holes 33, or, if desired, the lower end of the sheet may be cut from the glass in the tank by lifting the shields a short distance and allowing the heat or flames to cut off the sheet near the level of the bath by a melting action, the shields then being swung down to their normal position. A moving blowpipe may be used to move across the glass sheet near its lower end and sever it from the glass-bath by the intense cutting-flame.

As the sheet is drawn upwardly within the drawing-chamber its temperature is gradually reduced and the sheet becomes set or stiened into form. After it has been severed at its lower end it is lifted into the position shown in Fig. 4 and thence taken through an annealing-leer 39. This leer connects with one end of the drawing-chamber, and the leer is normally cut ofr1 from this chamber and itself separated into different chambers by horizontally-swinging dampers 40, provided with projecting levers 11, connected by rod 42.

ITO

These dampers are actuated by a cord 43, connected to one of the lever-arms and passing' down over suitable pulleys 44. The leer-walls are preferably made hollow and heated by suitable burners 45, which may be regulated so that the temperature will be gradually lowered as the glass sheet is carried through the leer.

The top of the leer-chamber is closed by swinging plates 46, a narrow slot being left between their inner ends for the passage of the sheet-holder. The leer is provided above the top of the annealing-chamber with parallel longitudinal bars 47, supported upon suitable hangers 4S, with anarrow space between them for the bait-holder. Below and in line with these stationary bars are movable bars 49. having downwardly projecting' webs which lit within grooved pulleys 50, carried upon shafts 51, pivoted at their outer ends to brackets ',lhese pulleys are moved vertically by bell-crank levers 53, having depending links provided with straps taking about the inner portions of the shafts. The bellcrank levers are actuated by connecting-rods 5i, the ends of which are connected bychains 55 to sprocket-wheels 56, secured to a common shaft 5T. @ne of the wheels or pulleys is provided with a lever-arm 58, having a depending cord 59, by means of which the shaft may berocked and the supporting-pulleys 5l) thus raised or lowered simultaneously. 'lhe two movable bars are connected at their outer ends by a plate and are moved longitudinally over the supporting pulleys by cords 6l, passing over pulley 62.

After the drawn sheet has been cut off and raised into the position shown in Fig. l the movable bars are slid forward on each side of the bait-carrier until the bars are beneath the lugs 1T. lhe bait Carrier or holder is then lowered to allow the lugs to rest on these bars and carrythe weight of the sheet and holder, the spring-jaws of the drawing-frame springing outwardly and releasing themselves from the hooks 1T. lhe dampers 4l) are, then opened, the movable bars lifted and drawn rearwardly, so as to bring the sheet into the lirst chamber of the leer. lhe pulleys 50 are then lowered, allowing the hooks 16 of the bait-holder to rest on the stationary bars. The dampers are then closed. Another drawingtool, with a bait clamped therein, is then hung on the frame 20, and the bait being lowered into the bath another sheet is drawn, as before. '.lhe movable bars are again slid forward and engaged with the lugs 1T of the next baitholder. The pulleys and movable bars then being' lifted and the dam pers opened, the bars are drawn rearwardly, thus. bringing the lirst sheet into the next chamber of the leer and the second sheet into the first chamber. The dampers LLO are then closed.

These operations are continued, and the sheets as they emerge from the leer may be received upon a car 63. (Shown in Fig. This car is provided with supporting-rods (Hi for the glass sheets and with separat-ing bars 65, which are wound with asbestos and project between the sheets. The bait-lmhilers are detached from th(` sheets at this point, the car being' moved along' slightly as each sheet is inserted until its interior is lilled, when it may be moved away and another car brought into position.

lheadvantages of myinvcntion result from the above-recited steps in the drawing operation, since thereby sheets or other articles of glass of an even thickness and of tine linish may be drawn directly from the molten bath.

lVhile I have shown one form of apparatus for carrying out my process, it will be understood that many other forms may be devised, both for drawing sheets and for drawing cylinders or other articles, without departure from my invention.

l. The method of making glass articles, which consists in drawing the glass upwardly from a molten bath and out of contact with any forming-surface, and retarding the eool ing of the article during the drawing to anneal the same and prevent breakage; substantially as described.

2. The method of forming glass articles, consisting in drawing glass from a molten bath upwardly in to an inclosed gaseous bath, while out of contact with any forming-surface and thereby retarding its cooling and annealing it; substantially as described.

3. The method of making sheet-glass, consisting in drawing a sheet upwardly from a body of molten glass, and holding out the edge portions of the sheet successively as it leaves the bath to prevent narrowing of the sheet; substantially as described.

a. The method of ,making glass articles, con

' sisting `in drawing the articles upwardly from a body of molten glass in a heated atmosphere confined about the glass, and shielding the molten glass at thc point at which the sheet is drawn, from thesurrounding heat; substantially as described.

The method of making sheet-glass, consisting in drawing the sheet upwardly from the body of molten glass, gripping the edge portions of the sheet to prevent its narrowing, and retarding the cooling of the sheet to anneal the same and prevent its breakage; substantially as described.

6. The-method of making glass articles,con sisting' in drawing the article upwardly from a body of molten glass out of Contact with any forming-surface, and into an inclosed gaseous bath, and then annealing the glass article; substantially as described.

7. The method of making glass articles, which consists in drawing` the glass upwardly IIO from a molten bath and out of Contact with any forming-surface, retarding the cooling of the article to prevent breakage, and then severing its lower end from the glass of the bath; substantially as described. l

8. The method of making glass articles, consisting in drawing the same upwardly from a body of molten glass, heating said body of glass, shielding the glass at the point at which the article is drawn, from the surrounding heat, and artificially cooling the article by radiation as it is drawn; substantially as described.

9. The method of forming glass articles, consisting in drawing the article upwardly from the molten bath out of contact with any forming-surface,` artificially cooling it by radiation as it is drawn, and then retarding cooling to prevent breakage; substantially as described.

10. rlhe method of making sheet-glass, consisting in drawing the same from a bath of molten glass, and retarding the cooling of the outer portions of the sheet more than the intermediate portion, to prevent warping; substantially as described.

ll. The method of making glass sheets, consisting in drawing the sheet from the molten bath, severing its lower end from the glass of the bath by melting the juncture and retarding cooling of the sheet; substantially as described.

12. The method of making sheet-glass, consisting in drawing a sheet upwardly from the molten bath, and stretching the edge portions of the sheet outwardly to prevent its narrowing; substantially as described.

13. The method of making sheet-glass, consisting in drawing a sheet upwardly from the molten bath into an inclosed gaseous bath while out of contact with any forming-sur-- face, and thence passing the sheet through a gradually-decreasing temperature; substantially as described.

14. The method of making sheet-glass, consisting in drawing a sheet upwardly from a molten bath, heating the bath, shielding the glass at the point at which the sheet is drawn, from the surrounding heat, retarding the cooling of the glass sheet, and then annealing the sheet; substantially as described.

l5. The method of forming glass sheets, consisting in drawing the sheet upwardly from the molten bath, stretching the edges of the sheet outwardly to prevent narrowing, retarding cooling of the sheet, and then annealing the sheet; substantially as described.

In testimony whereofI have hereunto set my hand.

JOHN H. LUBBERS.

lVitnesses:

MARSHALL H. RENO, L. A. CONNER, Jr. 

